This invention relates to relief valves and, more particularly, to a gas pressure relief valve which may be field retrofit onto an existing domestic gas pressure regulator.
At the present time, there are many pressure regulators installed for house service applications which function solely as gas pressure regulators. In other words, they merely regulate the pressure of gas in the outlet. However, as these regulators age, they tend not to shut off completely tight so that they let a small flow of natural gas get past the soft seat of the regulator. Under normal circumstances, a small amount of extra gas going past the regulator is no problem because most homes have pilot lights in their appliances that are constantly burning and any leakage of gas merely causes the pilot lights to burn a little bit brighter. However, under present day conditions where energy conservation is at a premium, many of the new appliances such as, for example, hot water heaters, stoves, ovens, heating furnaces, etc., do not have pilot lights. Instead, they utilize an electric ignition. Under such circumstances, if there is a flow of gas past the regulator, a dangerous gas pressure buildup can occur inside the home.
Normally, when regulators are new and shut off tightly, there is a penalty of slightly higher pressure on the downstream side. When this higher pressure is coupled with a little bit of sealing seat wear, there is a little extra flow at a slightly higher pressure and if this gas is not being burned by a pilot light, this can create a dangerous situation.
It is therefore an object of this invention to provide a pressure relief valve for a regulator used in house service applications.
Regulators exist that have built in pressure relief valves. However, it is economically undesirable to shut off the gas, take the old regulator out and put a new regulator in. This is both expensive and time consuming.
It is therefore an additional object of this invention to provide a pressure relief valve which may be retrofit onto an existing regulator without removing the regulator from the gas line.